Preparation procedures of spherical ultra-fine ε-HNIW by milling method

Spherical ultra-fine ε-HNIW particles were prepared by mechanical milling method. The physical structures and mechanical sensitivity of product HNIW, such as average particle size, particle size distribution and roundness, were highly affected by agitator's rotating speed, grinding duration, size of the grinding ball, filling rate of grinding balls within the mill chamber, dispersants and slurry concentration. The performance of the product HNIW was tested. The results show that the product HNIW particles are spherical, and the impact sensitivity of product HNIW is significantly reduced, while friction sensitivity is increased. Thermal stability is better than raw HNIW, and the polymorph remain unchanged. The smoothing and milling effect of milling ball with diameter of 5 mm is better, and the particle size distribution is uniform and concentrated, with size span down to 0.44 and roundness up to 0.85.